How likely is an equipment change for a medium-haul 777 that's showing flat bed F seats 5 months out? I'm buying a 1-way ORD-->SFO first ticket and am debating between VX and UA. Narrowbody, the choice is easily VX but if UA is flying a heavy with flat beds, the ability to earn miles and have more back-up options in case of disruptions makes them a bit more compelling. Both airlines are $423. If there's a good chance I'll get downgraded to a non-flat bed 777 then I'll probably book VX but if people say these have stayed true to what was advertised, I'd book United.

It's flight 769 on 6/20 ORD-->SFO and configuration 5 on this map: https://www.united.com/web/en-US/con...0/default.aspx The seat map shows this as "Polaris" but not sure if that's true on a mid-range Intercon, doubt it. But it's definitely not config 6 which shows it as a domestic first.